diff --git a/common/lambda-core/awssig4.js b/common/lambda-core/awssig4.js
index f9f9f35..85dcffb 100644
--- a/common/lambda-core/awssig4.js
+++ b/common/lambda-core/awssig4.js
@@ -14,7 +14,8 @@
  *  limitations under the License.
  */
 
-import utils from "./utils.js";
+import awscred from "./awscredentials.js";
+import utils   from "./utils.js";
 
 const mod_hmac = require('crypto');
 
@@ -252,6 +253,22 @@ function _splitCachedValues(cached) {
     return [eightDigitDate, kSigningHash]
 }
 
+/**
+ * Outputs the timestamp used to sign the request, so that it can be added to
+ * the 'x-amz-date' header and sent by NGINX. The output format is
+ * ISO 8601: YYYYMMDD'T'HHMMSS'Z'.
+ * @see {@link https://docs.aws.amazon.com/general/latest/gr/sigv4-date-handling.html | Handling dates in Signature Version 4}
+ *
+ * @param r {Request} HTTP request object (not used, but required for NGINX configuration)
+ * @returns {string} ISO 8601 timestamp
+ */
+function awsHeaderDate(r) {
+    return utils.getAmzDatetime(
+        awscred.getNow(),
+        utils.getEightDigitDate(awscred.getNow())
+    );
+}
+
 /**
  * Return a payload hash in the header
  *
@@ -267,6 +284,7 @@ function awsHeaderPayloadHash(r) {
 }
 
 export default {
+    awsHeaderDate,
     awsHeaderPayloadHash,
     signatureV4,
     // These functions do not need to be exposed, but they are exposed so that
diff --git a/common/lambda-core/lambda_ngx_http.conf b/common/lambda-core/lambda_ngx_http.conf
index 7c32e9d..aca0c2e 100644
--- a/common/lambda-core/lambda_ngx_http.conf
+++ b/common/lambda-core/lambda_ngx_http.conf
@@ -5,7 +5,7 @@ js_import /etc/nginx/serverless/lambdagateway.js;
 # This header is needed when doing v4 signature authentication. It
 # specifies the timestamp in which the signature was generated and is used with
 # the x-amz-date header.
-js_set $awsDate                 lambdagateway.awsHeaderDate;
+js_set $awsDate                 awssig4.awsHeaderDate;
 js_set $awsPayloadHash          awssig4.awsHeaderPayloadHash;
 js_set $awsSessionToken         awscredentials.sessionToken;
 js_set $lambdaFunctionARNAuth   lambdagateway.lambdaFunctionARNAuth;
diff --git a/common/lambda-core/lambdagateway.js b/common/lambda-core/lambdagateway.js
index 4b4a4a7..a642eb0 100644
--- a/common/lambda-core/lambdagateway.js
+++ b/common/lambda-core/lambdagateway.js
@@ -202,33 +202,6 @@ function _isHeaderToBeStripped(headerName, additionalHeadersToStrip) {
     return false;
 }
 
-/**
- * Outputs the timestamp used to sign the request, so that it can be added to
- * the 'Date' header and sent by NGINX.
- *
- * @param r {Request} HTTP request object (not used, but required for NGINX configuration)
- * @returns {string} RFC2616 timestamp
- */
-function lambdaDate(r) {
-    return awscred.getNow().toUTCString();
-}
-
-/**
- * Outputs the timestamp used to sign the request, so that it can be added to
- * the 'x-amz-date' header and sent by NGINX. The output format is
- * ISO 8601: YYYYMMDD'T'HHMMSS'Z'.
- * @see {@link https://docs.aws.amazon.com/general/latest/gr/sigv4-date-handling.html | Handling dates in Signature Version 4}
- *
- * @param r {Request} HTTP request object (not used, but required for NGINX configuration)
- * @returns {string} ISO 8601 timestamp
- */
-function awsHeaderDate(r) {
-    return utils.getAmzDatetime(
-        awscred.getNow(),
-        utils.getEightDigitDate(awscred.getNow())
-    );
-}
-
 function trailslashControl(r) {
     if (APPEND_SLASH) {
         const hasExtension = /\/[^.\/]+\.[^.]+$/;
@@ -295,12 +268,10 @@ function _isDirectory(path) {
 
 
 export default {
-    awsHeaderDate,
     editHeaders,
     lambdaFunctionARNAuth,
     lambdaFunctionARNHost,
     lambdaFunctionURLAuth,
-    lambdaDate,
     lambdaPort,
     lambdaProto,
     lambdaURI,
diff --git a/docs/development.md b/docs/development.md
index 79a9975..0d8c9a9 100644
--- a/docs/development.md
+++ b/docs/development.md
@@ -1 +1,7 @@
 # Development Guide
+
+## Integrating with AWS Signature
+
+## Extending the Gateway
+
+### Examples